Shielded electric light bulb



March 31, 1953 v K 2,633,549

SHIELDED ELECTRIC LIGHT BULB Filed June 18, 1952 v 2 SHEETS-SHEET 1 INVENTOR.

I BY S M. J. KING SHIELDED ELECTRIC LIGHT BULB March 31, 1953 2 SHEETS-SHEET 2 Filed June 18, 1952 IN V EN TOR. fifZ/zej B Patented Mar. 31, 1953 UNITED STATES PATENT OFFICE SHIELDED ELECTRIC LIGHT BULB Mike J. King, Danville, Ill. Application June 18, 1952, Serial No. 294,192

8 Claims.

This invention relates to a new and improved internally shielded light bulb and more particu larly to such a bulb for use on drop cords and in which an internal shield may be adjusted to a desired position andmay be frictionally held in adjusted position. 7

While the internal device is referred to as a shield, the inner surface of the shield may serve as a reflector so that the device shields in one direction and directs a beam of light in the opposite direction.

In a number of uses of electric light bulbs for general illuminating purposes it is desirable to shield the light in one direction so that it will not shine directly into the eyes of a person, such as a workman, close to the bulb. While external shields and shades have been used for this purpose they serve to out oh the light in large areas and reduce the general illumination of the area.

It is an object of the present invention to provide a new and improved electric light bulb for use on drop cords and having an internal light shield.

It is a further object to provide a bulb of this character in which the internal shield may be adjusted within the bulb.

It is an additional object to provide such a bulb in which the shield is rotatably supported within the bulb and may be moved upon its support by gravity.

It is another object to provide such a shield with a counterbalance and with internal, gravity acting means for clamping it in adjusted position.

Other and further objects will appear as the description proceeds.

- I have shown certain preferred embodiments of my invention in the accompanying drawing in which- Figure 1 is a side elevation, partly broken away, showing the bulb and shield construction;

T Figure 2 is a section taken on line 2-2 of Figure 1; I

T .Figure 3 is a partial section similar to Figure 1, but showing the counterbalance and clamping device in a different position;

Figure 4 is a side elevation of the bulb as used in a drop cord in a wire cage, the cage being partly broken away;

Figure 5 is a fragmentary side elevation of a shield support arm; and

Figure 6 is a perspective view of'a support arm.

In the drawing the electric light bulb is shown as having the usual metallic screw base II and 2 the glass bulb l3 in which the filament I5 is supported on the central stem is. The filament i5 is connected to the terminals at the base i l by the usual lead wires I1 and it. The stem 46 is usually formed of glass and in the present construction has an upper extended portion 13 located between integral shoulders 2i and 22 formed as part of the stem. The filament i5 is shown as supported by wires 24 inclining downwardly from the shoulder 2i.

' The shield assembly comprises a generally spherically curved shield member 26 carried on a'support arm 28. The support arm 28 has a wider lower portion 38 having spaced upturned lateral flanges 32 and 33. As best shown in Figure 2, these flanges 32 and 33 are provided with notches 33 which fit over the upper portion it of the stem between the shoulders 2i and 22 so that the support arm 28 is rotatably mounted on the stem. It will be understood that the arouate inner portion of the notches 35 is slightly larger than the entrance portion 33 of the notch so that the metal of the flanges 32 will spring over the stem portion l9 and when once in place will retain the support arm against displacement from the stem while permitting it to rotate freely thereon. s

The support arm 28 has a lower portion 31 which extends away from the stem portion is on the side opposite the shield 26. This portion 3? carries a pivot pin 39 which is located at right angles to the stem portion l9. The clamping and counterbalanced member M has an upper fiat portion 43 which is pivoted on the pin 39. This flat portion t3 passes through slots 44 formed in the side flanges 32 and 33 of the support arm 28. The flat portion 43 of the clamping member M has upturned flanges 45 and 46 located outside of flanges 32 and 33 which stifien the upper portion of the member The upper faces of the cuterlportion of member 43 are provided with outturned contact surface members 48 and 43 which are adapted to engage the adjacent stem shoulders '22 and 2i when the member ii is at its opposite limits'of movement. The member 41 at its lower end carries a' ball-shaped counterweight which may be formed of glass or metal or other suitable material.

It will be understood that the shield assembly and clamping assembly generally may be formed of glass or any suitable material such as metal, preferably light metal such, for example, as aluminum. In. the use of the device it will be apparent that the'contact s'urfacestfi or 9 will frictionally engage the stemsho'ulders22 or 2! when the bulb is so positioned that the clamping member is swung to one or the other limiting position. For example, in Figure 1, the contact surface 49 engages shoulder 2|, while with the lamp bulb tilted in the opposite direction, as shown in Figure 3, or is suspended on a cord, as shown in Figure 4, the contact surface 48 engages the shoulder 22. It will be understood that the shoulders and contact surfaces may be roughened, if desired, so as to increase the frictional contact to insure the parts remaining in the desired adjusted position.

The location of the shield 26 will be adjusted after the lamp bulb is in position in a light socket in cases where the socket is such that it may be tilted freely as is the case with the socket pendant on a drop cord or the like. The bulb may be suspended in base down or tilted position by means of a hook 55 on an enclosing protective cage 5; as shown in Figure 4. The cage 51 is clamped to socket 59 as shown in the drawing. The normal variation in commercial sockets makes it impossible to predetermine the exact rotary position of any light bulb when screwed into the socket to make proper electrical contact. Since the desired location of the shield is determined by the relative locations of the light bulb and the worker or area which is to be shielded, the location of the shield must be adjusted for each particular installation. It will be apparent that the clamping means'is effective in all positions of the bulb except those positions closely adjacent the horizontal. The device will normally be manufactured with the counterbalance assembly heavier than the shield so that when the bulb is horizontal the shield will be uppermost and the counterbalance 5| will swing downwardly with a pendulum action as in this position of the bulb the parts are free to swing and rotate on the stem portion I 9. Once adjusted and returned to pendant position on a drop cord, the shield will be held in place by contact between surfaces 22 and 48 as shown in Figure 4.

It will be understood that the shape and proportions of the various parts may be modified to meet difierent conditions and shapes of bulbs. The shield 26 may be given any desired size and shape depending upon the location of the filament and the degree of shielding desired. As shown in the drawings, the shield support arm 28 is bent or offset slightly to better cover the filament 15 in the position in which it is shown inthe drawing. If it is desired that the shield also act as a reflector, its interior face may be provided with a bright surface coating.

As has been described, all adjustments are made completely from outside the electric light bulb. When some adjustments are made, they are automatically locked in position, especially when the light bulb is in a vertical position.

While certain preferred embodimentsof the invention have been shown byway of example, these are to be understood to be illustrative only as it is capable of variation to meet differing conditions and requirements and I contemplate such modifications as come within the spirit and scope of the appended claims.

I claim:

1. In a light bulb for use on drop cords or the like, an internal stem, a shield rotatably mounted on the stem and means for clamping the shieldin 'a selected rotary'position.

2. In a light bulb for use on drop cords or the like, an internal stem, a shield rotatably mounted on the stem and means-for clamping the shield 4 in a selected rotary position, said means comprising a pivoted member having porti ns d ed to frictionally engage the stem.

3. In a light bulb for use on drop cords or the like, an internal stem, a shield rotatably mounted on the stem and means for clamping the shield in a selected rotary position, said means comprising a pivoted member having portions adapted to frictionally engage the stem, the pivoted member being located opposite the shield.

4. In a light bulb for use on drop cords or the like, an internal stem extending axially into the bulb from the base and having a pair of spaced shoulders adjacent its upper end, a shield rotatably mounted between the shoulders on the stem and gravity operated means for engaging the stem to hold the shield in a selected rotary position.

5. In a light bulb for use on drop cords or the like, an internal stem extending axially into the bulb from the base and having a pair of spaced shoulders adjacent its upper end, a shield assembly comprising a support arm rotatably mounted between the shoulders on the stem and a shield carried by the arm adjacent the inner face of the bulb, the support arm havin a portion extending away from the stem opposite the shield and pivoted clamping means mounted on said portion of the support arm.

8. In a light bulb, an internal stem extending axially into the bulb from the base and having a pair of spaced shoulders adjacent its upper end, a shield assembly comprising a support arm rotatably mounted between the shoulders on the stem and a shield carried by the arm adjacent the inner face of the bulb, the support arm having a portion extending away from the stem opposite the shield and pivoted clamping means mounted on said portion of the support arm, the pivot for said clamping means being located at right angles to the stem.

7. In a light bulb, an internal stem extending axially into the bulb from the base and having a pair of spaced shoulders adjacent its upper end, a shield assembly comprising a support arm rotatably mounted between the shoulders on the stem and a shield carried by the arm adjacent the inner face of the bulb, the support arm having a portion extending away from the stem opposite the shield and pivoted clamping means mounted on said portion of the support arm, the pivot of said clamping means being located at right angles to the stem and the clamping means being provided with two contact surfaces located adjacent the two shoulders on the'stem. 1

8. In a light bulb, an internal stem extending axially into the bulb from the base and having a pair of spaced shoulders adjacent its upper end, a shield assembly comprising a support arm rotatably mounted between the shoulders on the stem and a shield carried by the-arm adjacent the inner face of the bulb, the support arm having a portion extending away from the stem opposite the shield and pivoted clamping means mounted on said portion of the support arm, the pivot for said clamping means being located at right angles to the stem and. the clamping means being provided with two contact surfaces located adjacent the two shoulders on the stem, the clamping means swinging freely by gravity through an are limited by the contact of each contact surface with the adjacent shoulder.

MIKE J. KING.

No references cited. I 

